EFFECT OF DAY AND NIGHT TEMPERATURE ALTERNATIONS ON MORPHOGENESIS IN DENDRANTHEMA GRANDIFLORUM (RAMAT.)

The difference (DIF) between day-temperature and night-temperature strongly influences plant morphogenesis such as internode length, flower stalk length, leaf area and plant height of Chrysanthemum (Dendranthema grandiflorum Ramt.). Positive DIF and temperature-rise treatment at the start of the day increased internode length and flower stalk length.
Three days photoperiodic re-lighting treatment during short day-length treatment promoted flower stalk length.
And upper leaf area.
Consisting of a morning-drop and negative DIF, treatment at the start of short day-length treatment or at a visible bud stage reduced growth of flower stalk and upper leaf.
Stem elongation rate (SER) was determined in light and in darkness under various temperature regimes.
SER was strongly light dependent under alternation 14-hour days and 10-hour nights.
Light-dark and dark-light transition had marked effects on SER. SER peaked immediately following the start of the night, and a minimum in SER occurred shortly after the start of the day, regardless positive or negative DIF.

XXV International Horticultural Congress, Part 5: Culture Techniques with Special Emphasis on Environmental Implications Chemical, Physical and Biological Means of Regulating Crop Growth in Ornamentals and Other Crops

M. Nonaka

Chrysanthemum, temperature, DIF, internode, leaf growth, plant height

https://doi.org/10.17660/ActaHortic.2000.515.19